The present invention relates in general to Voice over-Internet Protocol (VoIP) technology, and more particularly, to systems and methods of utilizing a spare telephony switch to provide services in a distributed VoIP system.
Distributed VoIP systems comprise a set of switches and servers distributed across multiple sites. Distributed VoIP systems offer applications enabled by the integration of computer systems with telephony services. The software that supports the computer-integrated functionality is often implemented as a client-server environment in which the participants or clients (distributed telephony users) communicate with a server. Computer-integrated features rely not only on a server's application platform, but also on the availability of the network, switches, servers, and application services.
Availability is important for VoIP systems. Availability is often used to compare VoIP systems to traditional phone service provided over the public switched telephone network (PSTN). To achieve required levels of availability, many VoIP systems have redundancies configured into the system that can be used in the event of a failure in the system. As an example, a conventional distributed VoIP system may be configured to have enough extra capacity on the switches at each site to support a switch failure. If a switch fails, the endpoints on the failed switch can be re-distributed to available switches at the same site. This redundancy cannot be shared with other sites, however, because each site has different configuration requirements. Thus, to achieve required levels of availability, redundant capacity is needed for each site.
The cost of providing such redundancy can be prohibitive. For example, an “N+1” level of redundancy requires sufficient extra capacity at each site to support the failure of any single switch. Availability can be improved by adding second, third, or fourth level redundancy. However, increasing redundancy by adding additional switches at each site is costly in a distributed VoIP system.
Thus, there is a need for improved systems and methods of providing redundancy in a distributed VoIP system.